The radioactive decay of \(^{56}\) Ni and \(^{56}\) Co produces both gamma-rays and
positrons, which deposit their energy in the SN ejecta and thus power the
SN light curve. Gamma-rays carry most of the radioactive energy released by the decay. Positrons are responsible for only \(\approx 3.6\) % of it. Deposition is computed using a Montecarlo method, as outlined in [1]} and [2]}. Constant opacities are used for both processes: \(\kappa _{\gamma }=0.027\)  cm\(^2\) g\(^{-1}\)  for gamma-rays and \(\kappa _{e^+}=7\)  cm\(^2\) g\(^{-1}\)  for positrons. At the times considered here the density in the ejecta is still high enough that gamma-rays deposit efficiently enough to make the dominant contribution to the energy deposition, despite the significantly lower opacity to which they are subjected.
